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Spin-orbit entangled materials have attracted widespread interest due to the novel magnetic phenomena arising from the interplay between spin-orbit coupling and electronic correlations. However, the intricate nature of spin interactions within Kiteav materials complicates the precise measurement of low-energy spin excitations. Using Na2Co2TeO6 as an example, we study these low-energy spin excitations using the time-resolved resonant elastic x-ray scattering (tr-REXS). Our observations unveil remarkably slow spin dynamics at the magnetic peak, whose recovery timescale is several nanoseconds. This timescale aligns with the extrapolated spin gap of ~1 μeV, obtained by density matrix renormalization group (DMRG) simulations in the thermodynamic limit. The consistency demonstrates the efficacy of tr-REXS in discerning low-energy spin gaps inaccessible to conventional spectroscopic techniques. [ABSTRACT FROM AUTHOR]

Spin qubits in germanium gate-defined quantum dots have made considerable progress within the last few years, partially due to their strong spin-orbit coupling and site-dependent g-tensors. While this characteristic of the g-factors removes the need for micromagnets and allows for the possibility of all-electric qubit control, relying on these g-tensors necessitates the need to understand their sensitivity to the confinement potential that defines the quantum dots. Here, we demonstrate a S − T_ qubit whose frequency is a strong function of the voltage applied to the barrier gate shared by the quantum dots. We find a g-factor that can be approximately increased by an order of magnitude adjusting the barrier gate voltage only by 12 mV. We show how this strong dependence could potentially be attributed to the dots moving through a variable strain environment in our device. This work not only reinforces previous findings that site-dependent g-tensors in germanium can be utilized for qubit manipulation, but reveals the sensitivity and tunability these g-tensors have to the electrostatic confinement of the quantum dot. [ABSTRACT FROM AUTHOR]

The magnetoelectric (ME) effect is a fundamental concept in modern condensed matter physics and represents the electrical control of magnetic polarisations or vice versa. Two-dimensional (2D) van-der-Waals (vdW) magnets have emerged as a new class of materials and exhibit novel ME effects with diverse manifestations. This review emphasizes some important recent discoveries unique to vdW magnets: multiferroicity on two dimensions, spin-charge correlation, atomic ME effect and current-induced intrinsic spin-orbit torque, and electrical gating control and magnetic control of their electronic properties. We also highlight the promising route of utilizing quantum magnetic hetero- or homo-structures to engineer the ME effect and corresponding spintronic and optoelectronic device applications. Due to the intrinsic two-dimensionality, vdW magnets with those ME effects are expected to form a new, exciting research direction. [ABSTRACT FROM AUTHOR]

The topological Hall effect is a hallmark of topologically non-trivial magnetic textures such as magnetic skyrmions. It quantifies the transverse electric current that is generated once an electric field is applied and occurs as a consequence of the emergent magnetic field of the skyrmion. Likewise, an orbital magnetization is generated. Here we show that the charge currents are orbital polarized even though the conduction electrons couple to the skyrmion texture via their spin. The topological Hall effect is accompanied by a topological orbital Hall effect even for s electrons without spin-orbit coupling. As we show, antiferromagnetic skyrmions and antiferromagnetic bimerons that have a compensated emergent field, exhibit a topological orbital Hall conductivity that is not accompanied by charge transport and can be orders of magnitude larger than the topological spin Hall conductivity. Skyrmionic textures serve as generators of orbital currents that can transport information and give rise to considerable orbital torques. Magnetic skyrmions are nano-scale whirls that give rise to a topological Hall effect. The authors predict that this charge transport is accompanied by the transport of orbital angular momentum: a topological orbital Hall effect arises. [ABSTRACT FROM AUTHOR]

Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT), an experimental and theoretical study of changes in the electronic structure (dispersion dependencies) and corresponding modification of the energy band gap at the Dirac point (DP) for topological insulator (TI) have been carried out with gradual replacement of magnetic Mn atoms by non-magnetic Ge atoms when concentration of the latter was varied from 10% to 75%. It was shown that when Ge concentration increases, the bulk band gap decreases and reaches zero plateau in the concentration range of 45–60% while trivial surface states (TrSS) are present and exhibit an energy splitting of 100 and 70 meV in different types of measurements. It was also shown that TSS disappear from the measured band dispersions at a Ge concentration of about 40%. DFT calculations of band structure were carried out to identify the nature of observed band dispersion features and to analyze the possibility of magnetic Weyl semimetal state formation in this system. These calculations were performed for both antiferromagnetic (AFM) and ferromagnetic (FM) ordering types while the spin-orbit coupling (SOC) strength was varied or a strain (compression or tension) along the c-axis was applied. Calculations show that two different series of topological phase transitions (TPTs) may be implemented in this system, depending on the magnetic ordering. In the case of AFM ordering, the transition between TI and the trivial insulator phase passes through the Dirac semimetal state, whereas for FM phase such route admits three intermediate states instead of one (TI—Dirac semimetal—Weyl semimetal—Dirac semimetal—trivial insulator). Weyl points that form in the FM system along the direction annihilate when either the SOC strength decreases or a sufficient tensile strain is applied, which is accompanied by the corresponding TPTs. Model calculations of the influence of local magnetic ordering in AFM were carried out by alternating Mn layers with Ge-doped layers and showed that the magnetic Weyl semimetal state in this system is reachable at a Ge concentration of approximately 40% without application of any external magnetic fields. [ABSTRACT FROM AUTHOR]

Various photoactive molecules contain motifs built on aza-aromatic heterocycles, although a detailed understanding of the excited state photophysics and photochemistry in such systems is not fully developed. To help address this issue, the non-adiabatic dynamics operating in azanaphthalenes under hexane solvation was studied following 267 nm excitation using ultrafast transient absorption spectroscopy. Specifically, the species quinoline, isoquinoline, quinazoline, quinoxaline, 1,6-naphthyridine, and 1,8-naphthyridine were investigated, providing a systematic variation in the relative positioning of nitrogen heteroatom centres within a bicyclic aromatic structure. Our results indicate considerable differences in excited state lifetimes, and in the propensity for intersystem crossing vs internal conversion across the molecular series. The overall pattern of behaviour can be explained in terms of potential energy barriers and spin-orbit coupling effects, as demonstrated by extensive quantum chemistry calculations undertaken at the SCS-ADC(2) level of theory. The fact that quantum chemistry calculations can achieve such detailed and nuanced agreement with experimental data across a full set of six molecules exhibiting subtle variations in their composition provides an excellent example of the current state-of-the-art and is indicative of future opportunities for rational design of photoactive molecules. Aza-aromatic heterocycles are interesting motifs present in various photoactive molecules, however, their rational design remains challenging due to the lack of details about their excited state photophysics and photochemistry. Here, the authors combine experimental and theoretical studies of UV photoexcitation and associated relaxation dynamics for six azanaphthalenes exhibiting compositional variations, interrogating the difference in excited state lifetimes and the propensity for intersystem crossing vs internal conversion across the molecular series. [ABSTRACT FROM AUTHOR]

Most Rashba spin splitting experimentally studied so far has ideal lattice with inversion symmetry broken, which limits the possibility to minimize the presence of spin-degenerate carriers near the Fermi level. Here, we report a novel 2D Au2Sb surface alloy decorated with periodic structural defects that exhibits modulation on the Rashba spin-orbit coupling band. Spin- and angle-resolved photoemission spectroscopy reveals a Rashba spin-split band with antiparallel spin polarization, significantly broadened compared to the Au₂Sn surface alloy. From the good agreement between the experimental results and DFT calculations, we identify that the broadening of the Rashba bands comes from variations in Sb atom corrugation induced by the periodic three-pointed star-shaped defects. These periodic defects can shift the energy position of the Rashba bands without breaking the in-plane rotational and mirror symmetries. Our findings highlight the potential to tune spin-dependent properties in 2D materials for spintronic applications. [ABSTRACT FROM AUTHOR]

Unconventional superconductivity, where electron pairing does not involve electron-phonon interactions, is often attributed to magnetic correlations in a material. Well known examples include high-Tc cuprates and uranium-based heavy fermion superconductors. Less explored are unconventional superconductors with strong spin-orbit coupling, where interactions between spin-polarised electrons and external magnetic field can result in multiple superconducting phases and field-induced transitions between them, a rare phenomenon in the superconducting state. Here we report a magnetic-field driven phase transition in β-PdBi2, a layered non-magnetic superconductor. Our tunnelling spectroscopy on thin PdBi2 monocrystals incorporated in planar superconductor-insulator-normal metal junctions reveals a marked discontinuity in the superconducting properties with increasing in-plane field, which is consistent with a transition from conventional (s-wave) to nodal pairing. Our theoretical analysis suggests that this phase transition may arise from spin polarisation and spin-momentum locking caused by locally broken inversion symmetry, with p-wave pairing becoming energetically favourable in high fields. Our findings also reconcile earlier predictions of unconventional multigap superconductivity in β-PdBi2 with previous experiments where only a single s-wave gap could be detected. β-PdBi2 superconducting properties have been known about since the 1950s, with various works since then indicating the possibility of multiple superconducting gaps and unconventional superconductivity. However, so far only a single gap s-wave superconductivity was detected. Here, using tunnelling spectroscopy under an applied magnetic field, Powell et al observe a transition from s-wave to nodal pairing. [ABSTRACT FROM AUTHOR]

Topological superconductivity has attracted significant attention due to its potential applications in quantum computation, but its experimental realization remains challenging. Recently, monolayer Td−MoTe2 was observed to exhibit gate tunable superconductivity, and its in-plane upper critical field exceeds the Pauli limit. Here, we show that an in-plane magnetic field beyond the Pauli limit can drive the superconducting monolayer Td−MoTe2 into a topological superconductor. The topological superconductivity arises from the interplay between the in-plane Zeeman coupling and the unique Ising plus in-plane spin-orbit coupling (SOC) in the monolayer Td−MoTe2. The Ising plus in-plane SOC plays the essential role to enable the effective px + ipy pairing. As the essential Ising plus in-plane SOC in the monolayer Td−MoTe2 is generated by an in-plane polar field, our proposal demonstrates that applying an in-plane magnetic field to a gate tunable 2D superconductor with an in-plane polar axis is a feasible way to realize topological superconductivity. Topological superconductivity is the holy grail for implementing fault-tolerant quantum computation. Here, the authors show that for a superconducting monolayer Td−MoTe2 characterized by the Ising plus in-plane spin-orbit coupling, applying an in-plane magnetic field can drive it to a topological superconductor. [ABSTRACT FROM AUTHOR]

Topological superconductivity has attracted significant attention due to its potential applications in quantum computation, but its experimental realization remains challenging. Recently, monolayer Td−MoTe2 was observed to exhibit gate tunable superconductivity, and its in-plane upper critical field exceeds the Pauli limit. Here, we show that an in-plane magnetic field beyond the Pauli limit can drive the superconducting monolayer Td−MoTe2 into a topological superconductor. The topological superconductivity arises from the interplay between the in-plane Zeeman coupling and the unique Ising plus in-plane spin-orbit coupling (SOC) in the monolayer Td−MoTe2. The Ising plus in-plane SOC plays the essential role to enable the effective px + ipy pairing. As the essential Ising plus in-plane SOC in the monolayer Td−MoTe2 is generated by an in-plane polar field, our proposal demonstrates that applying an in-plane magnetic field to a gate tunable 2D superconductor with an in-plane polar axis is a feasible way to realize topological superconductivity. Topological superconductivity is the holy grail for implementing fault-tolerant quantum computation. Here, the authors show that for a superconducting monolayer Td−MoTe2 characterized by the Ising plus in-plane spin-orbit coupling, applying an in-plane magnetic field can drive it to a topological superconductor. [ABSTRACT FROM AUTHOR]

Efficient light generation from triplet states of organic molecules has been a hot yet demanding topic in academia and the display industry. Herein, we propose a strategy for developing triplet emitter by creating heterostructures of organic chromophores and transition metal dichalcogenides (TMDs). These heterostructures emit microsecond phosphorescence at room temperature, while their organic chromophores intrinsically exhibit millisecond phosphorescence under vibration dissipation-free conditions. This enhancement in phosphorescence is indicative of significantly enhanced spin-orbit coupling efficiency through coupling with TMDs. Through detailed studies on these hybrids from various perspectives, we elucidate key features of each component essential for generating microsecond triplet emission, including 2H-TMDs with heavy transition metals and aromatic carbonyl with an ortho-hydroxy group. Our intriguing findings open avenues for exploring the universal applicability of fast and stable hybrid triplet emitters. Metal-organic charge transfer has been the inevitable core of microsecond triplet emitters. Here the authors hybridize organic chromophores with transition-metal dichalcogenides to realize microsecond phosphorescence without metal-organic ligand bonding. [ABSTRACT FROM AUTHOR]

In this work, we perform first-principles computations on the structural, electronic, optical and transport properties of the rocksalt and orthorhombic phases of SnTe. Previous experimental and theoretical results have shown good correlation with the optimized lattice parameters of SnTe in both phases. All the calculations are performed based on the density functional theory (DFT) with the generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ) exchange-correlation potentials. The electronic structure calculation using the mBJ potential reveals a direct band gap in the rocksalt phase which decreases when spin-orbit coupling is incorporated, while a semi-metallic behavior is observed in the orthorhombic phase. Optical properties including dielectric function, absorption, reflectivity, etc. are analyzed showing significant phase-dependent variations with spin-orbit coupling having a noticeable effect at lower energies. Additionally, transport property analysis indicates that the orthorhombic phase has better thermoelectric performance making SnTe a promising material for optoelectronics and energy applications. [ABSTRACT FROM AUTHOR]

Some theoretical studies using perturbation and tight-binding methods have tried to shed light on the magnetic behaviors of carbon-based nanostructures in the limit of wave vector q = 0 . In a recent work, we studied a half-filled model of helical carbon chains to gain new insights for q ≠ 0 . Although in carbon the energy bands are usually derived from partially filled atomic p-shells, here we explore the hole contribution to these magnetic responses. We calculate the longitudinal spin susceptibility of an almost-filled tight-binding model of a helical chain for q ≠ 0 . We find that when the Fermi level lies at the band edges, the system shows for positive chirality a divergent paramagnetic susceptibility. This result is in agreement with that previously reported for the macroscopic limit q = 0 . [ABSTRACT FROM AUTHOR]

Due to the spin-orbit coupling, Dirac fermions, submerged in a thermal bath with finite macroscopic vorticity, exhibit a spin polarisation along the direction parallel to the vorticity vector Ω . Due to the symmetries of the Lagrangian for free massless Dirac particles, there are three independent and classically conserved currents corresponding to the vector, axial, and helical charges. The constitutive relations for the charge currents and the stress-energy tensor at thermal equilibrium, derived in the framework of quantum field theory at finite temperature, reveal vorticity-induced contributions that deviate from the perfect fluid form. In this paper, we consider the mode structure of the corresponding hydrodynamical theory and derive collective excitations associated with coherent fluctuations of all three charges. We show that the chirally imbalanced rotating fluid should possess non-reciprocal gapless waves that propagate with different velocities along and opposite to the vorticity vector. We also uncover a strictly unidirectional mode, which we call the axial vortical wave, propagating in the background of the axial charge density. The emergence of this wave can be traced back to earlier studies of vortical chiral fluids in a hydrodynamic approach. We also point out an unexpected instability in the limit of degenerate matter and discuss possible solutions when helicity and axial charge non-conservation are taken into account. [ABSTRACT FROM AUTHOR]

In the framework of the relativized quark model, the calculation of spin-orbit interactions is improved by considering the contribution from the light-quark cluster in a singly heavy baryon. It modifies the energy level splitting of the orbital excitation significantly and causes the emergence of fine structures for Σ Q , Ξ Q ′ and Ω Q baryons. Based on this improvement, we systematically analyze the fine structures and retest the heavy quark dominance mechanism. This mechanism is found to be violated in the 1P-wave states of the Σ c , Ξ c ′ and Ω c baryons although it remains effective overall, which may help to understand the nature of the heavy quarks and strong interactions. With the predicted fine structures, we make the precise assignments of those observed heavy baryons which once could not be accurately explained due to their close mass values. The method used in this work is instructive and applicable for the study of more complex exotic hadrons, such as the heavy tetraquarks and pentaquarks. [ABSTRACT FROM AUTHOR]

Symmetry invariants of a group specify the classes of quasiparticles, namely the classes of projective irreducible co-representations in systems having that symmetry. More symmetry invariants exist in discrete point groups than the full rotation group O(3), leading to new quasiparticles restricted to lattices that do not have any counterpart in a vacuum. We focus on the fermionic quasiparticle excitations under "spin-space group" symmetries, applicable to materials where long-range magnetic order and itinerant electrons coexist. We provide a list of 218 classes of new quasiparticles that can only be realized in the spin-space groups. These quasiparticles have at least one of the following properties that are qualitatively distinct from those discovered in magnetic space group(MSG)s, and distinct from each other:(i) degree of degeneracy,(ii) dispersion as function of momentum, and(iii) rules of coupling to external probe fields. We rigorously prove this result as a theorem that directly relates these properties to the symmetry invariants, and then illustrate this theorem with a concrete example, by comparing three 12-fold fermions having different sets of symmetry invariants including one discovered in MSG. Our approach can be generalized to realize more quasiparticles whose little co-groups are beyond those considered in our work. The symmetry of free space greatly restricts the properties of quasiparticles that exist in free space. Solid state systems, with the discrete symmetry of the crystal lattice, have far fewer restrictions, and here, Fang et al find a vast array of new quasiparticles, with distinct energy dispersions or external field couplings that can only be realised in the spin-space group. [ABSTRACT FROM AUTHOR]

Variational Monte Carlo (VMC) studies of extended Kitaev honeycomb models reveal a series of multinode quantum spin liquids (QSLs). They have an emergent Z2 gauge structure, a discrete number of symmetry-protected Majorana cones, and form Abelian or non-Abelian chiral spin liquids in applied magnetic fields. The large number of Z2 projective symmetry groups for spin–orbit-coupled states on the honeycomb lattice suggests that multinode QSLs can be found experimentally in future work on proximate Kitaev materials. [ABSTRACT FROM AUTHOR]

Josephson tunneling across a planar junction generally depends on the relative twist angle, θ, between the two layers. However, if under a discrete rotation, the order parameter in one layer is odd and the other is even (as, e.g., for a s-wave to d x 2 − y 2 -wave junction under a π/2 rotation) then the bulk Josephson current vanishes for all θ. Even in this case, we show that for a finite junction, the Josephson current, J, has a nonzero edge contribution that depends on θ and the orientation of the junction edges in ways that can serve as an unambiguous probe of the order parameter symmetry of any time-reversal preserving system (including multiband systems and those in which spin-orbit coupling is significant). We also analyze the microscopic considerations that determine the magnitude of J. [ABSTRACT FROM AUTHOR]

Correlated band theory implemented as a combination of the relativistic density functional theory with exact diagonalization [DFT+U(ED)] of the Anderson impurity term with Coulomb repulsion U in the 5f shell is applied to the magnetic field polarized state of . We demonstrate that the DFT+U(ED) approach provides a good agreement with very recent x-ray absorbtion near edge structure (XANES) and x-ray magnetic circular dichroism (XMCD) experiments. The branching ratio for the edge transitions of uranium, and the valence spin-orbit interaction per hole were evaluated in a perfect agreement with the XANES. The orbital-to-spin moment ratio is calculated with DFT+U(ED) within the range of values extracted from XMCD data. The uranium atom 5f-shell ground state with 33 of and 58 of configurations is determined. Both XMCD and DFT+U(ED) point out the intermediate valence of uranium as well as itinerant-localized dichotomy in . [ABSTRACT FROM AUTHOR]

We consider the anomalous, spin, valley, and valley spin Hall effects in a pristine graphene-based van-der-Waals (vdW) heterostructure consisting of a bilayer graphene (BLG) sandwiched between a semiconducting van-der-Waals material with strong spin-orbit coupling (e.g., WS 2 ) and a ferromagnetic insulating vdW material (e.g. Cr 2 Ge 2 Te 6 ). Due to the exchange proximity effect from one side and spin-orbit proximity effect from the other side of graphene, such a structure is referred to as graphene based 'ex-so-tic' structure. First, we derive an effective Hamiltonian describing the low-energy states of the structure. Then, using the Green's function formalism, we obtain analytical results for the Hall conductivities as a function of the Fermi energy and gate voltage. For specific values of these parameters, we find a quantized valley Hall conductivity. [ABSTRACT FROM AUTHOR]

Magneto-electric effect, i.e. an appearance of magnetisation induced by electric current, is allowed by symmetry in metals with crystal structure without space inversion. The microscopic origin of this effect is spin–orbit coupling of electrons with a non-centrosymmetric crystal lattice lifting spin degeneracy of electron energy and mixing spin and orbital degrees of freedom. The presented here calculation of magnetisation induced by current is based on the application of kinetic equation for the matrix distribution function of electrons occupying the states in two bands split by the spin–orbit interaction. [ABSTRACT FROM AUTHOR]

We studied theoretically the tunneling of electrons in ZnO/ZnCdO semiconducting double-barrier heterostructure with the application of an external electric field. Induced Rasbha spin-orbit interaction (RSOI) caused the spin-separation in the considered heterostructure. The addition of the Dresselhaus spin-orbit interaction (DSOI) enhances the separation between the different spin orientations. Even without in-built Rasbha spin-orbit interaction, one can obtain 100% spin-polarization efficiency in this heterostructure. The DSOI enhances the separation between spin-up and spin-down electrons on the energy scale. The increasing electric field reduces the energy of resonance spin-polarization and it reduces the spin-separation. The results might be helpful for the fabrication of ZnO-based spintronic devices. [ABSTRACT FROM AUTHOR]

Quantum critical points (QCPs), zero-temperature phase transitions, are windows to fundamental quantum-mechanical phenomena associated with universal behaviour. Magnetic QCPs have been extensively investigated in the vicinity of antiferromagnetic order. However, QCPs are rare in metallic ferromagnets due to the coupling of the order parameter to electronic soft modes. Recently, antisymmetric spin-orbit coupling in noncentrosymmetric systems was suggested to protect ferromagnetic QCPs. Nonetheless, multiple centrosymmetric materials host FM QCPs, suggesting a more general mechanism behind their protection. In this context, CeSi2-δ, a dense Kondo lattice crystallising in a centrosymmetric structure, exhibits ferromagnetic order when Si is replaced with Ag. We report that the Ag-substitution to CeSi1.97 linearly suppresses the ferromagnetic order towards a QCP, accompanied by concurrent strange-metal behaviour. Herein, we suggest that, despite the centrosymmetric structure, spin-orbit coupling arising from the local noncentrosymmetric structure, in combination with nonsymmorphic symmetry, can protect ferromagnetic QCPs. Our findings offer a general guideline for discovering new ferromagnetic QCPs and highlight one new family of materials within which the interplay of topology and quantum phase transitions can be investigated in the context of strongly correlated systems. Quantum critical points in metallic ferromagnets are rare and their mechanism is poorly understood. Here the authors report a ferromagnetic quantum phase transition in the dense ferromagnet CeSi2 with Ag-substitution and propose a general mechanism rooted in nonsymmorphicity in locally noncentrosymmetric systems. [ABSTRACT FROM AUTHOR]

Organic semiconductors (OSCs) are featured by weak spin-orbit coupling due to their light chemical element composition, which enables them to maintain spin orientation for a long spin lifetime and show significant potential in room-temperature spin transport. Carrier mobility and spin lifetime are the two main factors of the spin transport performance of OSCs, however, their ambiguous mechanisms with molecular structure make the development of spintronic materials really stagnant. Herein, the effects of halogen substitution in bay-annulated indigo-based polymers on carrier mobility and spin relaxation have been systematically investigated. The enhanced carrier mobility with an undiminished spin lifetime contributes to a 3.7-fold increase in spin diffusion length and a record-high magnetoresistance of 8.7% at room temperature. By analyzing the spin-orbit coupling and hyperfine interaction, it was found that the distance of the substitution site from the conjugated center and the nitrogen atoms in the molecules play crucial roles in spin relaxation. Based on the above results, we proposed a molecular design strategy of halogen substitution far from conjugate center to enhance spin transport efficiency, presenting a promising avenue for advancing the field of organic spintronics. The spin transport mechanism remains unclear for organic semiconductors. Here, authors investigate the effect of halogen substitution in bay-annulated indigo-based polymers and reveal the distance of substitution site from conjugated center and nitrogen atoms play crucial roles in spin relaxation. [ABSTRACT FROM AUTHOR]

The emergence of strong relativistic spin-orbit effects in low-dimensional systems provides a rich opportunity for exploring unconventional states of matter. Here, we present a route to realise tunable relativistic band structures based on the lateral patterning of proximity-induced spin-orbit coupling. The concept is illustrated on a patterned graphene–transition metal dichalcogenide heterostructure, where the spatially periodic spin-orbit coupling induces a rich mini-band structure featuring massless and massive Dirac bands carrying large spin Berry curvature. The envisaged systems support robust and gate-tunable spin Hall responses driven by the quantum geometry of mini-bands, which can be tailored through metasurface fabrication methods and twisting effects. These findings open pathways to two-dimensional quantum material design and low-power spintronic applications. Engineering sizeable spin-orbit coupling (SOC) in graphene generates effects unmatched in traditional low-dimensional systems. Here, the authors show that the periodic modulation of SOC in 1D patterned graphene heterostructures leads to unusual mini-band structures with symmetry-protected Dirac cones featuring enhanced spin Berry curvature, which paves the way to tunable spin Hall responses. [ABSTRACT FROM AUTHOR]

Specific properties, such as surface Fermi arcs, features of quantum oscillations and of various responses to a magnetic field, distinguish Dirac semimetals from ordinary materials. These properties are determined by Dirac points at which a contact of two electron-energy bands occurs and in the vicinity of which these bands disperse linearly in the quasimomentum. This work shows that almost the same properties are inherent in a wider class of materials in which the Dirac spectrum can have a noticeable gap comparable with the Fermi energy. In other words, the degeneracy of the bands at the point and their linear dispersion are not necessary for the existence of these properties. The only sufficient condition is the following: In the vicinity of such a quasi-Dirac point, the two close bands are well described by a two-band model that takes into account the strong spin-orbit interaction. To illustrate the results, the spectrum of ZrTe5 is considered. This spectrum contains a special quasi-Dirac point, similar to that in bismuth. Dirac semimetals are 3D materials where the conduction and valence bands meet at what are called Dirac points. The author shows that almost all the properties inherent in the Dirac semimetals are exhibited by a wider class of materials that need not have the gapless Dirac points. [ABSTRACT FROM AUTHOR]

Holes in silicon quantum dots are promising for spin qubit applications due to the strong intrinsic spin-orbit coupling. The spin-orbit coupling produces complex hole-spin dynamics, providing opportunities to further optimise spin qubits. Here, we demonstrate a singlet-triplet qubit using hole states in a planar metal-oxide-semiconductor double quantum dot. We demonstrate rapid qubit control with singlet-triplet oscillations up to 400 MHz. The qubit exhibits promising coherence, with a maximum dephasing time of 600 ns, which is enhanced to 1.3 μs using refocusing techniques. We investigate the magnetic field anisotropy of the eigenstates, and determine a magnetic field orientation to improve the qubit initialisation fidelity. These results present a step forward for spin qubit technology, by implementing a high quality singlet-triplet hole-spin qubit in planar architecture suitable for scaling up to 2D arrays of coupled qubits. Hole-spin qubits based on semiconductor quantum dots offer potential advantages over their electron-spin counterparts, such as fast qubit control and enhanced coherence times. Liles et al. report a hole-based singlet-triplet spin qubit in planar Si MOS device and develop a model to describe its dynamics. [ABSTRACT FROM AUTHOR]

The free-field switching of the perpendicular magnetization by the out-of-plane polarized spin current induced spin-orbit torque makes it a promising technology for developing high-density memory and logic devices. The materials intrinsically with low symmetry are generally utilized to generate the spin current with out-of-plane spin polarization. However, the generation of the out-of-plane polarized spin current by engineering the symmetry of materials has not yet been reported. Here, we demonstrate that paramagnetic CaRuO3 films are able to generate out-of-plane polarized spin current by engineering the crystal symmetry. The non-uniform oxygen octahedral tilt/rotation along film's normal direction induced by oxygen octahedral coupling near interface breaks the screw-axis and glide-plane symmetries, which gives rise to a significant out-of-plane polarized spin current. This spin current can drive field-free spin-orbit torque switching of perpendicular magnetization with high efficiency. Our results offer a promising strategy based on crystal symmetry design to manipulate spin current and could have potential applications in advanced spintronic devices. The authors realize generation of out-of-plane polarized spin current in perovskite oxide CaRuO3 with reduced crystal symmetry by engineering the oxygen octahedra, which can drive efficient field-free switching of perpendicular magnetization. [ABSTRACT FROM AUTHOR]

FePS3 is a layered van der Waals (vdW) Ising antiferromagnet that has recently been studied in the context of true 2D magnetism and emerged as an ideal material platform for investigating strong spin-phonon coupling, and non-linear magneto-optical phenomena. In this work, we demonstrate an important unresolved role of spin-orbit coupling (SOC) in the ground state and excitations of this compound. Combining first-principles calculations with linear flavor wave theory (LFWT), we find strong mixing and spectral overlap of different spin-orbital single-ion states. Low-lying excitations form hybrid spin-orbit exciton/magnon modes. Complete parameterization of the low-energy model requires nearly half a million coupling constants. Despite this complexity, such a model can be inexpensively derived using local many-body-based approaches, which yield quantitative agreement with recent experiments. The results highlight the importance of SOC even in first-row transition metals and provide essential insight into the properties of 2D magnets with unquenched orbital moments. [ABSTRACT FROM AUTHOR]

Engineered spin-electric coupling enables spin qubits in semiconductor nanostructures to be manipulated efficiently and addressed individually. While synthetic spin-orbit coupling using a micromagnet is widely investigated for driving and entangling qubits based on single spins in silicon, the baseband control of encoded spin qubits with a micromagnet in isotopically purified silicon has been less well investigated. Here, we demonstrate fast singlet-triplet qubit oscillation (~100 MHz) in a gate-defined double quantum dot in 28Si/SiGe with an on-chip micromagnet with which we show the oscillation quality factor of an encoded spin qubit exceeding 580. The coherence time T2* is analyzed as a function of potential detuning and an external magnetic field. In weak magnetic fields, the coherence is limited by frequency-independent noise whose time scale is faster than the typical data acquisition time of ~100 ms, which limits the T2* below 1 μs in the ergodic limit. We present evidence of sizable and coherent coupling of the qubit with the spin states of a nearby quantum dot, demonstrating that appropriate spin-electric coupling may enable a charge-based two-qubit gate in a (1,1) charge configuration. [ABSTRACT FROM AUTHOR]

We study systematically magnetic moments of hiddden-bottom pentaquark states with quantum numbers J P = 1 2 ± , J P = 3 2 ± , and J P = 5 2 ± with molecular, diquark–diquark–antiquark, and diquark–triquark models. The numerical results show that magnetic moments are different within the same model according to same quantum numbers and spin-orbit couplings. The results are also different when different models are taken into account with the same angular momentum. The magnetic moments encode valuable information about inner structures. We believe that our results may be helpful for experimental studies. [ABSTRACT FROM AUTHOR]

Despite the discovery of multiple intrinsic magnetic topological insulators in recent years the observation of Chern insulators is still restricted to very low temperatures due to the negligible charge gaps. Here, we uncover the potential of heavy transition-metal compounds for realizing a collinear antiferromagnetic Chern insulator (AFCI) with a charge gap as large as 300 meV. Our analysis relies on the Kane-Mele-Kondo model with a ferromagnetic Hund coupling J H between the spins of itinerant electrons and the localized spins of size S. We show that a spin-orbit coupling λ SO ≳ 0.03 t , where t is the nearest-neighbor hopping element, is already large enough to stabilize an AFCI provided the alternating sublattice potential δ is in the range δ ≈ S J H . We establish a remarkable increase in the charge gap upon increasing λ SO in the AFCI phase. Using our results we explain the collinear AFCI recently found in monolayers of CrO and MoO with charge gaps of 1 and 50 meV , respectively. In addition, we propose bilayers of heavy transition-metal oxides of perovskite structure as candidates to realize a room-temperature AFCI if grown along the [111] direction and subjected to a perpendicular electric field. [ABSTRACT FROM AUTHOR]

Superconductivity in quasicrystals poses a new challenge in condensed matter physics. We measured the resistance and ac magnetic susceptibility of a Ta1.6Te dodecagonal quasicrystal, which is superconducting below Tc ~ 1 K. We show that the upper critical field increases linearly with a large slope of − 4.4 T/K with decreasing temperature down to 0.04 K, with no tendency to level off. The extrapolated zero-temperature critical field exceeds the Pauli limit by a factor of 2.3. We also observed flux-flow resistance with thermally activated behavior and an irreversibility field that is distinct from the upper critical field. We discuss these peculiarities in terms of the nonuniform superconducting gap and spin-orbit interaction in quasicrystal structures. [ABSTRACT FROM AUTHOR]

The pairing symmetry of Sr2RuO4 is a long-standing fundamental question in the physics of superconducting materials with strong electronic correlations. We use the functional renormalization group to investigate the behavior of superconductivity under uniaxial strain in a two-dimensional realistic model of Sr2RuO4 obtained with density functional theory and incorporating the effect of spin-orbit coupling. We find a dominant d x 2 − y 2 superconductor mostly hosted by the dxy-orbital, with no other closely competing superconducting state. Within this framework, we reproduce the experimentally observed enhancement of the critical temperature under strain and propose a simple mechanism driven by the density of states to explain our findings. We also investigate the competition between superconductivity and spin-density wave ordering as a function of interaction strength. By comparing theory and experiment, we discuss constraints on a possible degenerate partner of the d x 2 − y 2 superconducting state. [ABSTRACT FROM AUTHOR]

Quantum links can interconnect qubit registers and are therefore essential in networked quantum computing. Semiconductor quantum dot qubits have seen significant progress in the high-fidelity operation of small qubit registers but establishing a compelling quantum link remains a challenge. Here, we show that a spin qubit can be shuttled through multiple quantum dots while preserving its quantum information. Remarkably, we achieve these results using hole spin qubits in germanium, despite the presence of strong spin-orbit interaction. In a minimal quantum dot chain, we accomplish the shuttling of spin basis states over effective lengths beyond 300 microns and demonstrate the coherent shuttling of superposition states over effective lengths corresponding to 9 microns, which we can extend to 49 microns by incorporating dynamical decoupling. These findings indicate qubit shuttling as an effective approach to route qubits within registers and to establish quantum links between registers. Spin shuttling is a promising technique for establishing a quantum link between qubit registers and has been studied in several quantum dot qubit platforms. Here the authors realize coherent shuttling of a hole spin qubit in a minimal quantum dot chain in germanium despite strong spin-orbit coupling. [ABSTRACT FROM AUTHOR]

While considering the appearance of Dirac cones in spin–orbit coupled two-dimensional materials, Young and Kane (Phys Rev Lett 115:126803, 2015) have found that, in the absence of other symmetries, spatial-, time-reversal and vertical glide plane (or horizontal screw rotation) symmetry give four-fold degenerate Dirac point at the time-reversal invariant momentum along the fractional translation. Here we show in which cases additional symmetries lead to Dirac line instead of Dirac cone in the band structure. We found three centrosymmetric, non-symmorphic layer double groups with line-like degeneracies instead of nodal points. We show that besides these Dirac lines, no other band contacts occur, including the accidental ones. Our results are illustrated using a tight binding example arising from s-orbitals on two atoms in the primitive cell. Finally, we discussed ways towards realistic materials where such features in the electronic dispersion are expected to appear. [ABSTRACT FROM AUTHOR]

Density-functional theory (DFT) is utilized to study the crystal structure, geometry, and magnetic and electronic properties of the triple perovskites Ba3MRu2O9 (M = Fe, Co, and Ni) in hexagonal phase with space group P63/mmc. Generalized gradient approximation plus Hubbard potential is found to be an effective potential for the treatment of these perovskites. Spin-orbit coupling with Hubbard U (GGA+SOC+U) is also applied to analyze its effect on the understudy compounds. The optimized crystal structures and geometries are consistent with the experimental reported results. The stability of these perovskites is described by cohesive and formation energies. The antiferromagnetic (AFM) nature of all these perovskites is confirmed by stable magnetic phase energies and magnetic susceptibility. The electronic band profiles in the AFM phase and electrical resistivities confirm that these perovskites are metallic in nature. Metallicity as well as magnetism in these compounds is due to d-state electrons of the M and Ru atoms. The metallic AFM nature reveals that these compounds are promising materials for magnetic cloaking, high-speed switching devices, and spintronic applications. [ABSTRACT FROM AUTHOR]

Interest in hybrid quasi-one-dimensional systems with an inner semiconducting part coated with a superconductor (the so-called core/shell structure) has been grown in the last decade. Materials with a strong spin‒orbit coupling and a large g-factor (InAs, InSb) are chosen as semiconductors. Due to the proximity effect, such objects can be considered as superconducting wires, where the existence of Majorana states has been predicted. This review briefly summarizes the current experimental studies aimed at the detection of Majorana quasiparticle excitations in superconducting wires. Furthermore, prospects of using the interference geometry of devices including such wires are discussed. In particular, the coherent transport in a spatially inhomogeneous one-dimensional normal metal/superconductor/normal metal system, where normal metal wires serve as arms of an interference device, which interact with a normal metal contact, has been analyzed theoretically. It has been found that responses of Majorana and Andreev low-energy excitations of the device can be distinguished. [ABSTRACT FROM AUTHOR]

The concept of ferroelectricity is now often extended to include continuous inversion symmetry-breaking transitions in various metals and doped semiconductors. Paraelectric metals near ferroelectric quantum criticality, which we term 'quantum paraelectric metals,' possess soft transverse optical phonons which can have Rashba-type coupling to itinerant electrons in the presence of spin-orbit coupling. We find through the Kubo formula calculation that such Rashba electron-phonon coupling has a profound impact on electron spin transport. While the spin Hall effect arising from non-trivial electronic band structures has been studied extensively, we find here the presence of the Rashba electron-phonon coupling can give rise to spin current, including spin Hall current, in response to an inhomogeneous electric field even with a completely trivial band structure. Furthermore, this spin conductivity displays unconventional characteristics, such as quadrupolar symmetry associated with the wave vector of the electric field and a thermal activation behavior characterized by scaling laws dependent on the phonon frequency to temperature ratio. These findings shed light on exotic electronic transport phenomena originating from ferroelectric quantum criticality, highlighting the intricate interplay of charge and spin degrees of freedom. [ABSTRACT FROM AUTHOR]

In this first-principles investigation, we explore the polymorphic features of pseudo-cubic alloys, focusing on the impact of mixing organic and inorganic cations on their structural and electronic properties, configurational disorder, and thermodynamic stability. Employing an automated cluster expansion within the generalized quasichemical approximation (GQCA), our results reveal how the effective radius of the organic cation (rMA = 2.15 Å, rFA = 2.53 Å) and its dipole moment (μMA = 2.15 D, μFA = 0.25 D), influences Glazer's rotations in the A1−xCsxPbI3 (A = MA, FA) sublattice, with MA-based alloy presenting a higher critical temperature (527 K) and being stable for x > 0.60 above 200 K, while its FA analog has a lower critical temperature (427.7 K) and is stable for x < 0.15 above 100 K. Additionally, polymorphic motifs magnify relativistic effects, impacting the thermodynamic behavior of the systems. Our methodology leverages the SimStack framework, an automated scientific workflow that enables the nuanced modeling of polymorphic alloys. This structured approach allows for comprehensive calculations of thermodynamic properties, phase diagrams, optoelectronic insights, and power conversion efficiencies while meticulously incorporating crucial relativistic effects like spin-orbit coupling (SOC) and quasi-particle corrections. Our findings advocate for the rational design of thermodynamically stable compositions in solar cell applications by calculating power conversion efficiencies using a spectroscopic limited maximum efficiency model, from which we obtained high efficiencies of about 28% (31–32%) for MA1−xCsxPbI3 with 0.50 < x < 1.00 (FA1−xCsxPbI3 with 0.0 < x < 0.20) as thermodynamically stable compositions at room temperature. The workflow's significance is highlighted by a Colab-based notebook, which facilitates the analysis of raw data output, allowing users to delve into the physics of these complex systems. Our work underscores the pivotal role of composition and polymorphic degrees in determining the stability and optoelectronic properties of MHP alloys. It demonstrates the effectiveness of the SimStack workflow in advancing our understanding of these materials. [ABSTRACT FROM AUTHOR]

Nowadays there is considerable interest in the photogalvanic effect in low-dimensional devices. In this work, we built a two-dimensional Bi2C-based photodetector and explored the spin-dependent photogalvanic effect under linearly polarized light and zero-bias conditions which can produce experimentally observable photoelectron flow. It was discovered that by introducing vacancies and substitution-doping into the Bi2C photodetector, the photogalvanic effect could be enhanced by 10–100 times that of a pristine photodetector, which is sufficient to be detected in experiments. Moreover, due to strong spin–orbit interactions, the Bi2C photodetector can produce very high spin polarization, even 100% full spin polarization, and pure spin current at a specific incident angle and photon energy, for example in the Bi1-vacancy Bi2C photodetector. In addition, the photon energy of incident light can regulate the produced spin photocurrent, which shows considerable anisotropy. Our results highlight the potential of the Bi2C photodetector as a versatile device in optoelectronics and spintronics applications. [ABSTRACT FROM AUTHOR]

Recently, the coexistence of topology and superconductivity has garnered considerable attention. Specifically, the dimensionality of these materials is crucial for the realization of topological quantum computation. However, the naturally grown materials, especially with one-dimensional feature that exhibits the coexistence of topology and superconductivity, still face challenges in terms of experimental realization and scalability, which hinders the fundamental research development and the potential to revolutionize quantum computing. Here, we report the first experimental synthesis of quasi-one-dimensional InNbS2 nanoribbons that exhibit the coexistence of topological order and superconductivity via a chemical vapor transport method. Especially, the in-plane upper critical field of InNbS2 nanoribbons exceeds the Pauli paramagnetic limit by more than 2.2 times, which can be attributed to the enhanced spin-orbit coupling and the weakened interlayer interaction between the NbS2 layers induced by the insertion of In atoms, making InNbS2 exhibit spin-momentum locking similar to that of monolayer NbS2. Moreover, for the first time, we report the superconducting diode effect in a quasi-one-dimensional superconductor system without any inherent geometric imperfections. The measured maximum efficiency is manifested as 14%, observed at μ0H ≈ ±60 mT, and we propose that the superconducting diode effect can potentially be attributed to the presence of the nontrivial topological band. Our work provides a platform for studying exotic phenomena in condensed matter physics and potential applications in quantum computing and quantum information processing. [ABSTRACT FROM AUTHOR]

The hope for a futuristic global quantum internet that provides robust and high-capacity quantum information transfer lies largely on qudits, the fundamental quantum information carriers prepared in high-dimensional superposition states. However, preparing and manipulating N-dimensional flying qudits as well as subsequently establishing their entanglement are still challenging tasks, which require precise and simultaneous maneuver of 2 (N-1) parameters across multiple degrees of freedom. Here, using an integrated approach, we explore the synergy from two degrees of freedom of light, spatial mode and polarization, to generate, encode, and manipulate flying structured photons and their formed qudits in a four-dimensional Hilbert space with high quantum fidelity, intrinsically enabling enhanced noise resilience and higher quantum data rates. The four eigen spin–orbit modes of our qudits possess identical spatial–temporal characteristics in terms of intensity distribution and group velocity, thereby preserving long-haul coherence within the entirety of the quantum data transmission link. Judiciously leveraging the bi-photon entanglement, which is well preserved in the integrated manipulation process, we present versatile spin–orbit cluster states in an extensive dimensional Hilbert space. Such cluster states hold the promise for quantum error correction which can further bolster the channel robustness in long-range quantum communication. [ABSTRACT FROM AUTHOR]

Symmetry-protected band degeneracy, coupled with a magnetic order, is the key to realizing novel magnetoelectric phenomena in topological magnets. While the spin-polarized nodal states have been identified to introduce extremely-sensitive electronic responses to the magnetic states, their possible role in determining magnetic ground states has remained elusive. Here, taking external pressure as a control knob, we show that a metal-insulator transition, a spin-reorientation transition, and a structural modification occur concomitantly when the nodal-line state crosses the Fermi level in a ferrimagnetic semiconductor Mn3Si2Te6. These unique pressure-driven magnetic and electronic transitions, associated with the dome-shaped Tc variation up to nearly room temperature, originate from the interplay between the spin-orbit coupling of the nodal-line state and magnetic frustration of localized spins. Our findings highlight that the nodal-line states, isolated from other trivial states, can facilitate strongly tunable magnetic properties in topological magnets. The coupling between topological electronic properties and magnetic order offers a promising route for magnetoelectric control with great potential for both applications and fundamental physics. Here, Susilo et al demonstrate the rich tunability of magnetic properties in nodal-line magnetic semiconductor Mn3Si2Te6 using pressure as control knob. [ABSTRACT FROM AUTHOR]

Symmetry-protected band degeneracy, coupled with a magnetic order, is the key to realizing novel magnetoelectric phenomena in topological magnets. While the spin-polarized nodal states have been identified to introduce extremely-sensitive electronic responses to the magnetic states, their possible role in determining magnetic ground states has remained elusive. Here, taking external pressure as a control knob, we show that a metal-insulator transition, a spin-reorientation transition, and a structural modification occur concomitantly when the nodal-line state crosses the Fermi level in a ferrimagnetic semiconductor Mn3Si2Te6. These unique pressure-driven magnetic and electronic transitions, associated with the dome-shaped Tc variation up to nearly room temperature, originate from the interplay between the spin-orbit coupling of the nodal-line state and magnetic frustration of localized spins. Our findings highlight that the nodal-line states, isolated from other trivial states, can facilitate strongly tunable magnetic properties in topological magnets. The coupling between topological electronic properties and magnetic order offers a promising route for magnetoelectric control with great potential for both applications and fundamental physics. Here, Susilo et al demonstrate the rich tunability of magnetic properties in nodal-line magnetic semiconductor Mn3Si2Te6 using pressure as control knob. [ABSTRACT FROM AUTHOR]

Coherent light-matter interactions mediated by opto-magnetic phenomena like the inverse Faraday effect (IFE) are expected to provide a non-thermal pathway for ultrafast manipulation of magnetism on timescales as short as the excitation pulse itself. As the IFE scales with the spin-orbit coupling strength of the involved electronic states, photo-exciting the strongly spin-orbit coupled core-level electrons in magnetic materials appears as an appealing method to transiently generate large opto-magnetic moments. Here, we investigate this scenario in a ferrimagnetic GdFeCo alloy by using intense and circularly polarized pulses of extreme ultraviolet radiation. Our results reveal ultrafast and strong helicity-dependent magnetic effects which are in line with the characteristic fingerprints of an IFE, corroborated by ab initio opto-magnetic IFE theory and atomistic spin dynamics simulations. Coherent light-matter interactions mediated by opto-magnetic phenomena like the inverse Faraday effect are expected to provide a non-thermal pathway for ultrafast manipulation of magnetism. The authors use intense and circularly polarized pulses of extreme ultraviolet radiation to induce particularly strong effects in a ferrimagnetic GdFeCo alloy. [ABSTRACT FROM AUTHOR]

The manipulation of spin textures by spin currents is of fundamental and technological interest. A particularly interesting system is the 2D van der Waals ferromagnet Fe3GeTe2, in which Néel-type skyrmions have recently been observed. The origin of these chiral spin textures is of considerable interest. Recently, it was proposed that these derive from defects in the structure that lower the symmetry and allow for a bulk vector Dzyaloshinsky-Moriya interaction. Here, we demonstrate current-induced domain wall motion in Fe3GeTe2 flakes, in which the maximum domain wall velocity is an order of magnitude higher than those reported in previous studies. In heterostructures with Pt or W layers on top of the Fe3GeTe2 flakes, domain walls can be moved via a combination of spin transfer and spin-orbit torques. The competition between these torques leads to a change in the direction of domain wall motion with increasing magnitude of the injected current. In this work, the researchers realize the current-induced motion of Néel type chiral domain walls via spin-transfer-torque in the pristine van der Waals ferromagnet Fe3GeTe2 and via spin-orbit-torques in heterostructures with platinum or tungsten. [ABSTRACT FROM AUTHOR]

In the research, the effects of the Rashba spin–orbit interaction (SOI) and magnetic field have been studied on the electronic and optical properties of a Frost–Musulin (FM) quantum dot. For this goal, the Schrödinger equation has been analytically solved by the Nikiforov–Uvarov (NU) procedure, and the energy states and the wave functions have been analytically derived. Using the analytical relations for optical properties, the total refractive index change (RIC) and absorption coefficient (AC) are calculated under a magnetic field with the Rashba SOI. The findings show that both the Rashba SOI and the magnetic field have a strong effect on the energy levels, RIC, and AC. The Rashba SOI causes the energy states to split into two branches, up and down. The peak locations of the RIC and AC move to higher energies when the magnetic field and Rashba coupling are increased. [ABSTRACT FROM AUTHOR]

We report a breakthrough in the hardware implementation of energy-efficient all-spin synapse and neuron devices for highly scalable integrated neuromorphic circuits. Our work demonstrates the successful execution of all-spin synapse and activation function generator using domain wall-magnetic tunnel junctions. By harnessing the synergistic effects of spin-orbit torque and interfacial Dzyaloshinskii-Moriya interaction in selectively etched spin-orbit coupling layers, we achieve a programmable multi-state synaptic device with high reliability. Our first-principles calculations confirm that the reduced atomic distance between 5d and 3d atoms enhances Dzyaloshinskii-Moriya interaction, leading to stable domain wall pinning. Our experimental results, supported by visualizing energy landscapes and theoretical simulations, validate the proposed mechanism. Furthermore, we demonstrate a spin-neuron with a sigmoidal activation function, enabling high operation frequency up to 20 MHz and low energy consumption of 508 fJ/operation. A neuron circuit design with a compact sigmoidal cell area and low power consumption is also presented, along with corroborated experimental implementation. Our findings highlight the great potential of domain wall-magnetic tunnel junctions in the development of all-spin neuromorphic computing hardware, offering exciting possibilities for energy-efficient and scalable neural network architectures. The authors demonstrate all-spin synapses and neurons using domain wall-magnetic tunnel junctions, utilizing synergistic spin-orbit torque and Dzyaloshinskii-Moriya interaction. The intrinsic linearity is required for compact and energy-efficient bio-inspired hardware for neuromorphic computing. [ABSTRACT FROM AUTHOR]

Organic room-temperature phosphorescence materials have attracted extensive attention, but their development is limited by the stability and processibility. Herein, based on the on-line derivatization strategy, we report the urea-formaldehyde room-temperature phosphorescence materials which are constructed by polycondensation of aromatic diamines with urea and formaldehyde. Excitingly, urea-formaldehyde room-temperature phosphorescence materials achieve phosphor lifetime up to 3326 ms. There may be two ways to enhance phosphorescence performance, one is that the polycondensation of aromatic diamine with urea and formaldehyde promotes spin-orbit coupling, and another is that the imidazole derivatives derived from the condensation of aromatic o-diamine with formaldehyde maintains low levels of energy level difference and spin-orbit coupling, thus achieving ultra-long afterglow. Surprisingly, urea-formaldehyde room-temperature phosphorescence materials exhibit tunable phosphorescence emission in electrostatic field. Accordingly, 1,4-phenylenediamine, urea, and formaldehyde are copolymerized and self-assembled into phosphorescence microspheres with different electrostatic potential strengths. By mixing 1 wt% 1,4-phenylenediamine polycondensation microspheres with 1,4-phenylenediamine free microspheres, phosphor lifetime of the composite could be regulated from 27 ms to 123 ms. Moreover, vulcanization process enables precise shaping of urea-formaldehyde room-temperature phosphorescence materials. This work not only demonstrates that urea-formaldehyde room-temperature phosphorescence materials are promising candidates for organic phosphors, but also exhibits the phenomenon of electrostatically regulated phosphorescence. Organic room temperature phosphorescent materials have useful properties, but development can be limited by processing and stability challenges. Here, the authors report a derivatisation strategy for the preparation of room temperature phosphorescent materials responsive to an electrostatic field. [ABSTRACT FROM AUTHOR]